Proto Melange
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Lithium isotopes in Guatemalan and Franciscan HP-LT Rocks: Insights into the role of sediment-derived fluids in the mantle wedge
description
Lithium isotopes in Guatemalan and Franciscan HP-LT Rocks: Insights into the role of sediment-derived fluids in the mantle wedge. Kyla Simons, George Harlow, Hannes Brueckner , Steven Goldstein, Sorena Sorensen, N. Gary Hemming, Charles Langmuir. Proto Melange. Oceanic Sediments. - PowerPoint PPT Presentation
Transcript of Proto Melange
Lithium isotopes in Guatemalan and Franciscan HP-LT Rocks:
Insights into the role of sediment-derived fluids in the mantle wedge
Proto Melange
Shear zone between plates
Altered Ocean Crust
Oceanic Sediments
After Bebout (2007)
Subduction Fluid Trace Element Patterns
HP-LT Rocks in Guatemala
Dehydra
tion of Slab
Shear zone between plates
Altered Ocean Crust
Oceanic Sediments
Physical Model Prograde
Physical Model Retrograde
Dehydra
tion of Slab
Shear zone between plates
Altered Ocean Crust
Oceanic Sediments
South have lawsonite cold and wet @ peak conditions (~480°C)
Very high pressure rocks just shy of coesite (UHP) field
North saw slightly higher-T (<550°C) with a second metamorphic event
Eclogites
JadeititesAppear to follow down-pressure trend from associated Lws-eclogites and blueschist-eclogites
South contains qtz higher P.
South T ≥ 200°C.
North T = 300-400°C
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Li systematics in Guatemala
MORBIAB
Guatemala Eclogite Avg.
